"QUANTUM: wells shed light on lightbulb alternative"
A promise of future lightbulb replacements that are almost 100 percent efficient came to light in a recent proof-of-concept experiment carried out by the National Nuclear Security Administration's Los Alamos National Laboratory and Sandia National Laboratories. In demonstrating these "light engines," experimental quantum wells emitted ultraviolet energy so rapidly that before that energy could become radiation, it was absorbed by integrated nanocrystals that glowed like a fluorescent tube. Now, "the process is 55 percent efficient," reported Sandia researcher Daniel Koleske, "because, unlike the fluorescent bulb, which must radiate its ultraviolet energy to the phosphor in the form of photons, the quantum well here delivers its ultraviolet energy to the nanocrystal very rapidly, before photons even form." As a consequence of the conversion process from UV photons to visible photons, normal fluorescent lightbulbs are less than 10 percent efficient. But in the future, light engines currently under development by companies working with the national laboratories could increase that efficiency to almost 100 percent.